Add landing page for kjol, documentation

go/webui/code_test.go

@@ -0,0 +1,99 @@
+package webui
+
+import (
+	"strings"
+	"testing"
+)
+
+// The highlighter emits HTML, and its input is Go source — which is full of <, > and &.
+// Anything that reaches the page unescaped is markup injection into your own docs page:
+// a snippet containing `<div>` would render a div.
+func TestHighlightGoEscapes(t *testing.T) {
+	got := HighlightGo(`s := "<div class=\"x\">" // a & b`)
+
+	if strings.Contains(got, "<div") {
+		t.Errorf("a `<div>` in the SOURCE reached the output as markup:\n%s", got)
+	}
+	if !strings.Contains(got, "&lt;div") {
+		t.Errorf("the angle bracket was not escaped:\n%s", got)
+	}
+	if !strings.Contains(got, "&amp;") {
+		t.Errorf("the ampersand was not escaped:\n%s", got)
+	}
+}
+
+func TestHighlightGoClassifies(t *testing.T) {
+	got := HighlightGo("func main() { x := 42 // note\n}")
+
+	for _, want := range []struct{ what, class, text string }{
+		{"keyword", goKeywordClass, "func"},
+		{"call", goFuncClass, "main"},
+		{"number", goNumberClass, "42"},
+		{"comment", goCommentClass, "// note"},
+	} {
+		if !strings.Contains(got, `<span class="`+want.class+`">`+want.text+`</span>`) {
+			t.Errorf("%s %q was not highlighted:\n%s", want.what, want.text, got)
+		}
+	}
+}
+
+// The //gowasm: directives are the most important line in half these snippets. They are
+// comments, and must survive as such.
+func TestHighlightGoKeepsDirectives(t *testing.T) {
+	got := HighlightGo("//gowasm:page / static layout=public\nfunc HomePage() {}")
+	if !strings.Contains(got, `<span class="`+goCommentClass+`">//gowasm:page / static layout=public</span>`) {
+		t.Errorf("the directive was not kept whole as a comment:\n%s", got)
+	}
+}
+
+// A lexer that can hang or eat the rest of the file on malformed input would take the
+// whole page down with it. Unterminated literals stop; they do not run away.
+func TestHighlightGoSurvivesMalformedInput(t *testing.T) {
+	for _, src := range []string{
+		`x := "unterminated`,
+		"y := `unterminated raw",
+		"/* unterminated block",
+		`z := '`,
+		"",
+	} {
+		got := HighlightGo(src)
+		// The text must all still be there — mangling is not an acceptable failure mode
+		// either. Compare on the visible characters, ignoring the spans.
+		if plain := stripTags(got); plain != src {
+			t.Errorf("input %q came out as %q", src, plain)
+		}
+	}
+}
+
+// Nothing is dropped: every byte of the source is still on the page, in order.
+func TestHighlightGoIsLossless(t *testing.T) {
+	src := "package app\n\nimport \"strings\"\n\nfunc f(n int) string {\n\treturn strings.Repeat(\"x\", n) // pad\n}\n"
+	if plain := stripTags(HighlightGo(src)); plain != src {
+		t.Errorf("the highlighter changed the source.\n got: %q\nwant: %q", plain, src)
+	}
+}
+
+// stripTags removes the spans and unescapes, recovering the original source.
+func stripTags(s string) string {
+	var b strings.Builder
+	for i := 0; i < len(s); {
+		if s[i] == '<' {
+			j := strings.IndexByte(s[i:], '>')
+			if j < 0 {
+				break
+			}
+			i += j + 1
+			continue
+		}
+		b.WriteByte(s[i])
+		i++
+	}
+	out := b.String()
+	// Reverse html.EscapeString, innermost last.
+	out = strings.ReplaceAll(out, "&lt;", "<")
+	out = strings.ReplaceAll(out, "&gt;", ">")
+	out = strings.ReplaceAll(out, "&#34;", `"`)
+	out = strings.ReplaceAll(out, "&#39;", "'")
+	out = strings.ReplaceAll(out, "&amp;", "&")
+	return out
+}